This invention relates to systems for preventing water from passing from the exterior of a block wall to the inside of a building. More specifically, the invention relates to a drainage system especially for collecting seepage water in and draining it from the interior cavities of a masonry block wall back to the outside of the wall.
For years, construction contractors have struggled with the problem of building a water-tight wall of masonry blocks. Masonry block walls are notorious for allowing water on the exterior side of the wall to enter into its central cavities through the joints between the blocks, or through the blocks themselves. Once water has entered into the block cavities, it tends to seep inside the building and cause moisture problems. Water within the blocks and on their surfaces damages interior and exterior wall finishes.
Elastomeric sealants are sometimes used to try to seal the outer surfaces of block walls. However, such sealants are not entirely effective, are expensive to apply, and obscure the natural appearance of the blocks where a natural look is desired.
There have been several other attempts to solve the problem of water seepage through masonry block walls. For example, some have tried using blocks in the bottom course that have openings to drain the water from inside the block cavities to a gravel bed, and subsequently into a drain tile. Examples of this type of system are shown in U.S. Pat. No. 4,612,742 to Bevilacqua, U.S. Pat. No. 4,333,281 to Scarfone, U.S. Pat. No. 3,852,925 to Gazzo, and U.S. Pat. No. 3,287,866 to Bevilacqua.
Others have tried to solve such problem by placing blocks at the bottom course that have interconnecting lateral slots which allow the water to drain laterally into an adjacent block. The water then drains to the exterior of the block wall by either a drain pipe extending from one of the blocks, as shown in U.S. Pat. No. 3,562,982 to Parezo, or by openings in the bottom course blocks which direct the water to a gravel bed and subsequently to a drain tile, as shown in U.S. Pat. No. 4,486,986 to Cosenza.
Still others have tried to solve the problem by placing a thin vent structure beneath the bottom block course to draw the water toward a gravel bed, which then directs the water to a drain tile. Such a system is shown in U.S. Pat. No. 4,381,630 to Koester.
One drawback of the above-mentioned drainage systems is that they do not prevent water within the block cavities from contacting and seeping through the walls of the interior block cavities as it drains down through such cavities. Water passing from upper courses to lower courses must run down the walls of the interior cavity, causing such walls to become saturated with water, which eventually seeps to the interior and exterior surfaces of the building.
Another drawback of previous drainage systems is that they drain water toward the inside of the building, rather than directing it to the exterior of the building. Such systems promote saturation of the ground underneath the wall and building structure, are difficult to install, and make access to the gravel bed and drain tile difficult.
Another major problem with previous drainage systems is that water tends to accumulate on top of the footing before it drains through holes in the block to the gravel bed. As tee water accumulates on top of the footing, it seeps through joints and cracks in the footing, which causes water to pass to the inside of the building.
Still another problem with prior drainage systems is that they do not collect water from the block cavities at a level other than the bottom course. Consequently, water that has entered a block wall at upper courses must run down the walls of the interior cavities to the bottom course before it drains. In doing so, water inherently contacts and seeps through the blocks to the inside of the building.
A primary object of the present invention, therefore, is to provide an effective water collection and drainage system and method for a masonry block wall which prevent water from passing from the exterior to the interior side of the wall by controlling and directing water flow within the wall.
Another object is to provide a water collection and drainage system and method which collect and remove water from interior cavities of a masonry block wall to the exterior of the wall.
Additional objects are to provide a water collection and drainage system which is easy to install during construction of a masonry block wall, and which is simple and inexpensive to manufacture.
Still another object is to provide a collection and drainage system and method which prevent water from accumulating at the top of a footing.
Another object is to provide a water collection and drainage system and method which collect water at several different levels of a block wall, direct it down through the interior cavities of the wall to a lower collection level, and finally direct it to the outside of the wall at such lower level.
Yet another object of the invention is to provide a water collection and drainage system and method which prevent water in upper interior cavities from draining down interior cavity walls to be absorbed by lower level blocks.